Interwoven versus Knitted Self-Expandable Metallic Stents: A Comparison Study of Stent-Induced Tissue Hyperplasia in the Rat Esophagus

Jeon Min Kang,Ji Won Kim,Jung-Hoon Park,Dong-Sung Won,Dongwook Oh,Yubeen Park,Sang Soo Lee,Dae Sung Ryu,Chu Hui Zeng,Song Hee Kim

doi:10.3390/app12010346

Jeon Min Kang, Ji Won Kim + Show 8 more

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https://doi.org/10.3390/app12010346

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Abstract

This study investigated whether interwoven self-expandable metallic stent (I-SEMS) placement suppresses stent-induced tissue hyperplasia compared with conventional knitted self-expandable metallic stent (K-SEMS) placement in a rat esophageal model. Twelve rats were randomly assigned to the I-SEMS (n = 6) and K-SEMS (n = 6) groups. All rats were sacrificed 4 weeks after the stent placement. The degree of stent-induced tissue hyperplasia on esophagography and histologic examination was compared between the groups. Stent placement was technically successful in all rats. Esophagography revealed significantly greater mean luminal diameter of the stented esophagus in the I-SEMS group than in the K-SEMS group (p < 0.001). Histologic examination revealed a significantly lower percentage of tissue hyperplasia area and a significantly thinner submucosal fibrosis in the I-SEMS group than in the K-SEMS group (all p < 0.001). There were no significant differences in the thickness of the epithelial layers (p = 0.290) and degree of inflammatory cell infiltration (p = 0.506). Formation of stent-induced tissue hyperplasia was evident with both I-SEMS and K-SEMS. Placement of I-SEMSs with a small cell size and high flexibility seems to be effective in suppressing stent-induced tissue hyperplasia compared with placement of K-SEMSs in rat esophageal models.

Highlights

Placement of hand-crafted and knitted self-expandable metallic stents (SEMSs; K-SEMSs) is the most common therapeutic strategy for malignant or benign esophageal strictures [1,2,3]
Procedural Outcomes Stent placement was technically successful in all rats, and all of them survived until the end of the study
Our results demonstrated that interwoven self-expandable metallic stent (I-SEMS) placement successfully inhibited stent-induced tissue hyperplasia caused by mechanical injury after stent placement in a rat esophageal model

Summary

Introduction

Placement of hand-crafted and knitted self-expandable metallic stents SEMSs) is the most common therapeutic strategy for malignant or benign esophageal strictures [1,2,3]. Or partially covered SEMSs have been developed for esophageal strictures to overcome this problem [6,7,8]. The covering membrane could prevent tissue hyperplasia through the wire meshes, granulation tissue formation could still occur at the uncovered ends of the stent [8,9]. Covered SEMS placement significantly increases the stent migration rate, and tissue ingrowth through the wire mesh can occur through the disrupted covering membrane [8,10]. Stent-induced tissue hyperplasia can lead to recurrent symptoms and technical difficulties in stent removal [2,3]

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